Flora of North America Volume 27 is the first volume of three on the bryphytes (mosses, hornworts, and liverworts). Thirty-five authors treat the first half of the mosses, including 32 of the acrocarpous families, with introductory chapters on bryophyte morphology, the history of North America floristic bryology, and economic uses. The 84 species of sphagnum, of considerable economic importance, are fully treated. The number of taxa total 37 genera and 621 species. The taxa are fully described and keyed, illustrated with an estimated 136 panels of detailed line drawings of two or more species each, and geographic distributions are provided at the province and state level. This is the first installment of a full compilation of the mosses for North America since A. J. Grout's Moss Flora of North America of 60 years ago, and is sure to be an invaluable reference.

The volume includes identification keys, descriptions, line drawings, and ecological characteristics for each of the species; distribution maps for the native and established species; and a list of the synonyms currently in use for the accepted names.